Iran to face ‘big problems’ if it does not adhere to nuclear deal: Trump

US President Donald Trump speaks during a Make America Great Again rally at the Covelli Centre in Youngstown, Ohio, July 25, 2017. (Photo by AFP)

US President Donald Trump has threatened Iran with “big, big problems” if Tehran fails to comply with the 2015 nuclear agreement.

His veiled warning comes a week after the White House certified to Congress that the Islamic Republic was complying with the agreement it signed with the P5+1 group of countries -- the US, Britain, France, China and Russia plus Germany.

"If that deal doesn’t conform to what it’s supposed to conform to, it's going to be big, big problems for them. That I can tell you. Believe me," Trump said during a speech in Youngstown, Ohio, on Tuesday.

"You would have thought they would have said 'thank you United States. We really love you very much.' Instead, they've become emboldened. That won’t take place much longer," he added.

Meanwhile, the Republican president told TheWall Street Journal on the same day that he would be surprised if Iran is in compliance with the nuclear deal when he should re-certify it in three months.

"We’ll talk about the subject in 90 days but I would be surprised if they were in compliance," he told the Journal in an interview.

The Trump administration notified Congress of Iran’s compliance for the first time in April. The certification that Iran is technically complying with the nuclear agreement clears the way for sanctions to remain lifted.

Under the agreement, limits were put on Iran’s nuclear activities in exchange for, among other things, the removal of all nuclear-related bans against the Islamic Republic.

The UN Security Council later unanimously endorsed a resolution that effectively turned the accord known as the JCPOA into international law.

On Tuesday, the Republican-controlled House of Representatives voted to impose new sanctions against Iran, Russia and North Korea. In a 419 to 3 vote, the lower chamber of the US Congress passed the sanctions package.

The bill includes sanctions against Iran and the Islamic Revolution Guards Corps (IRGC) for allegedly supporting terrorism, which it vehemently denies, and North Korea, for its missile tests.

The legislation also aims to punish Moscow for its alleged meddling in the 2016 presidential election and annexation of Crimea.

Elsewhere in his remarks, Trump, who is routinely criticized for his tweets, rejected the notion that he still lacks a presidential style.

"I'd say with the exception of the late great Abraham Lincoln, I can be more presidential than any president that’s held this office," he said. "But we have to move a little faster than that. We will never be beholden to the lobbyists or the special interests."